So one of the main differences is that spicypass is setup-free. You just pick a master password and go. It achieves this by using symmetric encryption via the libsodium library. A nice side-effect of this is that backups are as simple as copying the .spicypass file to your backup device/server. With asymmetric encryption you have to worry about backing up your private keys in addition to the store file(s).
Another major difference is that it has an idle lock. Even if someone has root access to your machine and you leave it unattended while spicypass is running, they won't be able to see your passwords (assuming there's no keylogger involved).
There's also the minimalist aspect. pass has a lot of features that I personally don't need and consider to be bloat. I designed spicypass to my own personal specs: A very simple notepad-like interface, but secure. I figure I can't be the only one who thinks all the bells and whistles that most password managers have just get in the way.
When I want to push to a git repo and authenticate with my private key, I just run git push normally, and a pin-entry prompt comes up, and I just need to enter my master password. Similarly, when I want to use a stored password for logging into a website, I just click the passff extension and enter my master password into the pinentry program. It would seem like something like spicypass would just bloat my system, requiring multiple programs for authenticating in different ways.
I can understand the drive for minimalism, but I can't see any reasonable metric by which pass could be seen as bloated - it provides a small set of features that are important for a password store and nothing more.
Given SpicyPass doesn't have that, I think I'll still be with Pass, because it's free and simply amazing.
I absolutely understand why this might turn some people off, maybe even most people. But I know that there are people (like me) who want something that isn't connected to the cloud, and isn't going to inherit all of the security flaws of their browser.
(Disclosure: I work for a commercial password manager that do offer browser extensions)
With that said I don't rule anything out for the future.